酯交换法合成碳酸二甲酯的催化剂研究

用ＺＳＭ－５分子筛作为甲醇和碳酸乙烯酯反应碳酸二甲酯 系的催化剂,通过对ＺＳＭ－５进行阳离子交换和浸渍法改性发现,ＺＳＭ－５分子筛碱性中心对反应起主要作用,适当强度的碱中心更有利于反应的正向进行。当甲 碳酸 乙酯的摩尔比为４：１,液时空速１ｍｌ／ｇｈ,反应温度１００℃,压力０．７ＭＰａ时,用碳酸钠改改性ＺＳＭ－５作催化剂,碳酸乙烯酯的转化率为５０％。     

5-硝基愈创木酚钠的合成

报道了５－硝基愈创木酚钠（５－ＮＧＳ）的合成方法。由愈创木酚与乙酐在１００℃回流１ ｈ 得到乙酰化产物。反应中生成的乙酸不必分离，再补加一定量乙酸作为下一步反应的溶剂。用发烟硝酸直接硝化上述乙酰化物，总收率高于７０％ 。用ＩＲ、１ＨＮＭＲ和ＭＳ对产物的结构进行了表征     

酶促酯化拆分-化学消旋串联法制备S-布洛芬

以消旋布洛芬为反应底物，探究了酶促酯化拆分布洛芬的工艺。利用南极假丝酵母脂肪酶B的对映体选择性催化布洛芬选择性酯化，并对醇的种类、反应介质、底物摩尔比、酶量、干燥剂种类和添加量、温度及时间等反应条件进行了优化，以56%的收率得到了光学纯的S-布洛芬，接下来对酯化产物进行化学法消旋。以二甲亚砜为反应介质，利用二异丙基氨基锂催化布洛芬发生外消旋反应，完全消旋后再进行酶促拆分仍能达到之前的效果。如此循环7次布洛芬的利用率可达到90%以上。     

季铵盐相转移催化合成N-异丙基二碳酰亚胺的研究

以季铵盐为催化剂，相转移催化合成Ｎ－异丙基－１－异丙基－４－甲基二环［２，２，２］－５－辛烯－２、３－二碳酰亚胺（ＴＭＲ）。讨论影响这一反应的主要因素，得出比较适宜的反应条件。通过ＩＲ、ＭＳ和１ＨＮＭＲ分析，证实产物的结构即为ＴＭＲ。     

硫化二硫化磷酸钼的合成及其性能的研究

研究了硫化氢对合成硫化二硫代磷酸钼（Ｓ－ＭｏＤＴＰ）的产率、产物钼含量及其润滑特性的影响。结果表明，硫化氢可提高合成Ｓ－ＭｏＤＴＰ产率１．０－２０．０％，增中其钼含量０．４－１．３％。只要０．５％Ｓ－ＭｏＤＴＰ的添加量，即可能使润滑油的摩擦系数降低５４．８％，其磨斑直径减少６０．８％。     

3,4—二氢—2H—吡喃—5—醛与脂肪二胺的反应研究

３，４－二氢－２Ｈ－吡喃－５－醛与脂肪二胺在水溶剂中，于低温下反应４８ｈ，得到Ｎ，Ｎ＇－二（２－羟丙基－３－氧代－１－丙烯基）二胺。产物经元素分析，ＩＲ，＾１ＨＮＭＲ和ＭＳ证实。     

3，4─二氢─2H─吡喃─5─醛与脂肪二胺的反应研究

３，４－二氢－２Ｈ－吡喃－５－醛与脂肪二胺在水溶剂中，于低温下反应４８ｈ，得到Ｎ，Ｎ′－二（２－羟两基－３－氧代－１－丙烯基）二胺。产物经元素分析，ＩＲ，１ＨＮＭＲ和ＭＳ证实。     

α—硝基环十二酮的合成

以环十二酮为原料合成了环十二－１－烯醇乙酸酯（收率７４％），再经硝化得标化合物（总收率６５％）。产物经ＩＲ，＾１ＨＮＭＲ，＾１３ＣＮＭＲ和ＭＳ确证。     

4′-庚氧基-4-联苯甲酸的合成

改进了４′－庚氧基－４－联苯甲酸的合成路线。经元素分析、ＩＲ、１ＨＮＭＲ和ＭＳ确证了中间产物４′－庚氧基－４－乙酰基联苯的结构。ＤＳＣ及织构图证实其具有液晶性。     

稀土加工助剂兼热稳定剂RHS—1

本文介绍一种新型无毒透明ＰＶＣ添加剂ＲＨＳ－１。ＲＨＳ－１的主要化学成分是一种难溶稀土有机酸盐，兼具加工助剂和热稳定剂的作用，作为加工助剂，其效能达到ＡＣＲ－２０１的二倍以上，ＲＨＳ－１的热稳定效能不及１７ＭＯＫ，但由于两者具体有协同作用，ＲＨＳ－１可用于代替部分１７ＭＯＫ。     

Enantioselective esterification of ibuprofen with ethanol as reactant and solvent catalyzed by immobilized lipase: experimental and molecular modeling aspects

BACKGROUND: In recent years enantioselective esterification of racemic ibuprofen performed in organic co‐solvent media such as isooctane and cyclohexane and catalyzed by lipases, has been proposed as an effective way to increase the concentration of S‐ibuprofen in the racemic mixture. In this contribution, the enantioselective enzymatic esterification of (R,S)‐ibuprofen with ethanol catalyzed by commercial Novozym 435 without the addition of a co‐solvent is thoroughly investigated. Experimental data are further analyzed considering the results of extensive molecular modeling calculations. RESULTS: The conversion of ibuprofen towards the ethyl esters and the enantiomeric excess towards S‐ibuprofen are greatly affected by the ethanol and water contents of the reaction media. The optimum conditions for the esterification of racemic ibuprofen in a batch‐type reactor were as follows: molar ratio of ethanol to ibuprofen = 7, 4.8% v/v of water, 160 mg of Novozym 435, 45 °C and 200 rpm. Under these conditions an enantiomeric excess of 54% and 63% of ibuprofen conversion were reached. CONCLUSIONS: Results showed that the reaction in excess of the esterifying alcohol in a system free of additional organic solvents is possible if the proper conditions are set. Molecular modeling calculations demonstrated that the formation of dead‐end compounds between the enzyme and ethanol/water may account for lipase inhibition at high concentrations of those compounds. Copyright © 2009 Society of Chemical Industry     

Effect of co‐solvent addition on the reaction kinetics of the lipase‐catalyzed resolution of ibuprofen ester

BACKGROUND: The addition of co‐solvent is not limited to enhancing the catalytic rate, it could also assist in situ racemization in the dynamic kinetic resolution of racemic compounds by increasing the reactivity of the base catalyst employed. In the current work, reaction media with the presence of DMSO were investigated in Candida rugosa lipase (EC 3.1.1.3)‐catalyzed hydrolysis of ibuprofen ester that focuses on the thermodynamic effect, reaction stability and implication for the kinetic parameters. RESULTS: The introduction of 2% DMSO increased the reaction rate, conversion, and enantioselectivity of the Candida rugosa lipase‐mediated resolution. However, the performance of the particular enzymatic reaction was reduced when a higher DMSO concentration was added. At lower reaction temperatures, the medium with 2% DMSO exhibited an increase in enantioselectivity, which was attributed to a higher activation energy difference between the fast‐ and slow‐reacting enantiomers compared with the water‐isooctane medium. Additionally, the presence of DMSO had a significant effect on the kinetic parameters, shown by a lower value of Michaelis constant compared with that of a normal reaction without DMSO, which resulted in a fast reaction rate. Finally, inhibition due to the uncompetitive substrate inhibitor was reduced, while the non‐competitive product inhibitor consequently increased. CONCLUSION: This work has demonstrated that only 2% of DMSO can be tolerated by the free Candida rugosa lipase in the resolution of ibuprofen ester. However, it is still able to give significant positive effects on the hydrolysis rate, kinetic parameters and enantioselectivity as well as reaction stability. © 2012 Society of Chemical Industry     

Total Synthesis of Symbioramide: a Flexible Approach for the Efficient Preparation of Structural Isomers

A concise, enantioselective total synthesis of symbioramide, starting from simple achiral compounds and racemic α‐amino‐β‐keto ester derivatives is reported. This highly flexible strategy allowed the efficient preparation of seven structural isomers of the natural product as well. The synthesis relies on a convergent route that involves the efficient stereoselective reduction of a α‐keto‐β‐yne ester, and the dynamic kinetic resolution of an α‐amino‐β‐keto ester through ruthenium‐mediated asymmetric hydrogenation.     

布洛芬甲酯的绿色合成工艺

以布洛芬和甲醇为原料,以对甲苯磺酸为催化剂,以甘油作为吸水剂和催化剂分离的溶剂,利用甘油与布洛芬甲酯可自动分层的特性,辅以柱色谱分离,建立了一种布洛芬甲酯的绿色合成工艺。整个工艺路线无三废产生。合成条件经正交实验优化,确定了最佳反应条件:反应体系的最佳组成为n(布洛芬):n(甲醇):n(甘油)=1:10.2:1.4,催化剂对甲苯磺酸的最佳添加量为布洛芬质量的1%,最佳转速为300 r/min,最佳反应时间为4h,在该条件下转化率可达97.1%,得率大于95.0%。经液相-质谱联用(LC/MS)检测,色谱纯度为99.9%。     

水-有机溶剂混溶体系中催化抗体催化拆分布洛芳脂

The asymmetric hydrolysis of racemic ibuprofen ester is one of the most important methods for chiral separation of ibuprofen. In this work, a catalytic antibody that accelerates the rate of enantioselective hydrolysis of ibuprofen methyl ester was obtained against an immunogen consisting of tetrahedral phosphonate hapten attached to bovine serum albumin (BSA). The catalytic activity of the catalytic antibody in the water-miscible organic-solvent system composed of a buffer solution and N, N-dimethylformamide (DMF) was studied. With 6% DMF in the buffer solution (containing catalytic antibody 0.25 μmol, 0.2 mol•L－1 phosphate buffer, pH 8) at 37°C for 10 h, a good conversion (48.7%) and high enantiomeric excess (>99%) could be reached. The kinetic analysis of the catalytic antibody-catalyzed reaction showed that the hydrolysis in the water-miscible organic-solvent system with DMF in buffer solution followed the Michaelis-Menten kinetics. The catalytic efficiency (Kcat/Km) was enhanced to 151.91 L•mmol－1•min－1, twice as large as that for the buffer solution only.     

高选择性脂肪酶的筛选及其拆分布洛芬

为了实现脂肪酶在有机相中对外消旋布洛芬的高效拆分,筛选得到了一株具有高立体选择性的脂肪酶产生菌-扩展青霉TS414(Penicillium expansum TS414). 实验探讨了水分、温度、有机溶剂、酶浓度、醇结构和醇浓度对酶促拆分反应的影响,确立了酯化反应的最佳反应体系：布洛芬6.46 mmol/L,脂肪酶53.3 mg/mL,正丙醇40 mmol/L,异辛烷15 mL,水0.5%(j),60℃条件下反应50 h. 在此条件下,拆分反应的转化率和对映体选择率分别为42%和429.63. 结果表明,Penicillium expansum TS414脂肪酶是一种较为理想的用于外消旋布洛芬拆分的工具酶,在布洛芬手性拆分方面具有广阔的应用前景.     

Transdermal Delivery Systems for Ibuprofen and Ibuprofen Modified with Amino Acids Alkyl Esters Based on Bacterial Cellulose

The potential of bacterial cellulose as a carrier for the transport of ibuprofen (a typical example of non-steroidal anti-inflammatory drugs) through the skin was investigated. Ibuprofen and its amino acid ester salts-loaded BC membranes were prepared through a simple methodology and characterized in terms of structure and morphology. Two salts of amino acid isopropyl esters were used in the research, namely L-valine isopropyl ester ibuprofenate ([ValOiPr][IBU]) and L-leucine isopropyl ester ibuprofenate ([LeuOiPr][IBU]). [LeuOiPr][IBU] is a new compound; therefore, it has been fully characterized and its identity confirmed. For all membranes obtained the surface morphology, tensile mechanical properties, active compound dissolution assays, and permeation and skin accumulation studies of API (active pharmaceutical ingredient) were determined. The obtained membranes were very homogeneous. In vitro diffusion studies with Franz cells were conducted using pig epidermal membranes, and showed that the incorporation of ibuprofen in BC membranes provided lower permeation rates to those obtained with amino acids ester salts of ibuprofen. This release profile together with the ease of application and the simple preparation and assembly of the drug-loaded membranes indicates the enormous potentialities of using BC membranes for transdermal application of ibuprofen in the form of amino acid ester salts.     

Synthesis of stereoisomers of 8-methyl-2-decanol and esters attractive to severalDiabrotica sp.

Details of the syntheses of the four stereoisomers of 8-methyl-2-decanol and its propanoate ester are given. The racemic ester, two of its stereoisomers, and one stereoisomer as an acetate are attractive to several species ofDiabrotica. The key steps in the syntheses involve high-performance liquid chromatograpic resolutions of diastereomers to achieve high configurational enrichment of each site and generation of (R)-2-methylbutyric acid by chemical degradation ofd-isoleucine.Mention of a commercial or proprietary product does not constitute an endorsement by the USDA.     

运用手性固定相研究外消旋布洛芬的光学分离

Ibprofen is widely used as a non-steroidal anti-inflammatory drug and poduced as racemic mixture.Its pharmacological activity resides only is S-( )-enantiomer,and R-(-)-enantiomer is not only inactive but also has many side effects.Thus it is necessary to separate Renantiomer from racemic ibuprofen.We studied optical separation of racemic Ibuprofen with chiral high performance liquid chromatography(HPLC).,Out of three different chiral stationary phases,which were selected on the basis of structure and availability,two were found to be effective.There was optimum eluent composition for each stationary phase for good resolution in optical separation.Resolution decreased with increase of eluent flow rate,but effect of injection volume on resolution was insignificant at high eluent flow rate.